Police said they have looked into White's history and said they believe he is suffering from mental health issues. Police said they discovered that White was recently involuntarily committed in another city and released.

We've also learned White was recently arrested by campus police for a DWI.

Investigators said White used a "Bowie-style" hunting knife and calmly walked around the plaza.

Video shows him being taken down by police.

"I just see everybody in a panic, in a frenzy, running away, and I look over towards the Gregory Gym area and I just see somebody like passed out on the floor, covered in blood," eyewitness Bryan Ramirez said. "I've never seen anything like this in my life, it's the craziest I've ever seen. I've never seen like horror-stricken faces like that in my life, it was just crazy, it was hectic."

Police said White walked up to a female student, kicked her out of the way and stabbed Brown. White calmly walked away and found another person sitting at a picnic table on the plaza. White stabbed him in the back of the head, police said.

White then walked toward the area of a food truck and stabbed a third and fourth victim.

He then went to the Jester West dorm where police found him walking toward more students with a knife. Two officers were able to take White down and into custody.

A murder charge and assault charges are pending against White.

Meanwhile, classes and events continued this morning on campus. The UT Counseling and Mental Health Center has extended its hours through Wednesday.

UT President Greg Fenves sent a message to the campus community asking for everyone to be "there for one another."